Noise in the detected output of small-area light-emitting diodes

The noise present in the detected optical output of three types of small-area electroluminescent diodes (GaAs diffused junctions (Al-Ga)As single and double heterostructures), operated continuously at high-current densities in a room-temperature ambient, has been measured in the frequency range of 300 Hz to 300 kHz. The best unit showed noise, with an
1/f
-type frequency dependence, which was less than twice the theoretical detector shot-noise limit at 350 Hz and that approached this shot-noise limit near 1.2 kHz.